How is the salami technique used as a negotiating tactic?

a$)$ to timely slice the item's value in half, so the deal seems fair.

b$)$ to heatedly pile on concessions to the other person, until that person is overwhelmed.

c$)$ to gradually shave multiple concessions off the other person.

d$)$ to lightly add on concessions to the other person, until the item's value is almos doubled.